CN107082740B - Method for improving yield of prenol prepared by chlorination process - Google Patents
Method for improving yield of prenol prepared by chlorination process Download PDFInfo
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Abstract
The invention discloses a method for improving the yield of prenol prepared by a chlorination method. When the prenol is prepared by the existing chlorination method, about 10 percent of 3-chloroprenol generated in the chlorination process is not a target product, the yield of the prenol is limited, and extra more solid wastes are generated. According to the method, 3-chloroisoamylene and 1-chloroisoamylene obtained by chloro addition reaction are not separated, and anhydrous formate or acetate is directly added for esterification; and then carrying out hydrolysis reaction in an alkali solution, converting the prenol formate or prenol acetate into prenol, converting 3-chloroisopentene into methyl butenol, rectifying the obtained organic layer to separate out methyl butenol, toluene and prenol, and recycling the methyl butenol and the toluene to the chloro addition reaction. The invention avoids the traditional rectification of the chloro isoamylene, thereby solving the problems of equipment corrosion, toxic chloride, damage to the chloride due to high temperature and the like caused by the rectification of the chloro isoamylene.
Description
Technical Field
The invention relates to the field of organic chemical synthesis, in particular to a method for improving the yield of prenol prepared by a chlorination method.
Background
The chemical name of the prenol is 3-methyl-2-buten-1-ol, and the prenol is an important fine chemical intermediate and can be used for synthesizing citral, pyrethroid insecticides and other fine chemicals. Currently, the main synthetic prenol routes are: 1) in BASF patent WO2008037693, Chinese patent CN103254036 and the like, formaldehyde and isobutene are adopted to generate 3-methyl-3-butene-1-alcohol through Prins reaction, and then the isopentenol is further generated through isomerization. 2) Chinese patents CN102924227, CN102584519 and the like take methyl butenol or isoprene as raw materials, and after esterification by chloro and sodium acetate, the prenol is obtained by further alkaline hydrolysis. From the perspective of atom economy, cleanness and environmental protection, the preparation of the prenol by the reaction of formaldehyde and isobutene is a better route, but the route needs high-temperature and high-pressure reaction conditions, the reaction conditions are very strict, the equipment investment is large, and certain safety risks are also provided. The chloro-addition method of methyl butenol and concentrated hydrochloric acid is used for synthesizing isopentene alcohol, reaction conditions are mild, equipment requirements are low, but about 10% of 3-chloro-isopentene produced in the chloro-addition process is not a target product, the yield of the isopentene alcohol is limited, and extra more solid wastes can be produced, mainly because 3-chloro-isopentene and 1-chloro-isopentene are in a balance in a reaction system in the chloro-isopentene synthesis process, the 3-chloro-isopentene and 1-chloro-isopentene always keep the ratio of 1: 8-1: 9, if a conventional rectification separation method is adopted for separation, the chloro-isopentene is unstable under a heated condition, can be further added with dissolved hydrogen chloride for chloro-addition, and can also be synthesized to produce new impurities; in addition, the chloroisoamylene is relatively corrosive to equipment, and steam of the chloroisoamylene also has relatively high toxicity. The separation and recovery of 3-chloroisoamylene and 1-chloroisoamylene are seriously influenced by the existence of a plurality of factors.
Disclosure of Invention
The technical problem to be solved by the invention is to overcome the defects in the prior art and provide a chlorination method for preparing prenol, which avoids rectification of chloroprenol, so as to improve the yield of the product prenol, reduce new impurities generated by rectification, reduce the discharge of waste and reduce the cost of raw materials for producing prenol.
Therefore, the invention adopts the following technical scheme: a method for improving the yield of the prenol prepared by a chlorination method is characterized in that 3-chloroisopentene obtained by chlorination addition reaction is not separated from 1-chloroisopentene, anhydrous formate or acetate is directly added for esterification, the 1-chloroisopentene is converted into prenol formate or prenol acetate, and the 3-chloroisopentene is dissolved in the prenol formate or prenol acetate; and then carrying out hydrolysis reaction in an alkali solution (3-chloroisopentene does not participate due to steric hindrance), converting the prenyl alcohol formate or prenyl alcohol acetate into prenyl alcohol and converting the 3-chloroisopentene into methyl butenol after the hydrolysis is finished, rectifying the obtained organic layer to separate the methyl butenol and the prenol, and recycling the methyl butenol to the chloro addition reaction.
According to the method, about 10% of 3-chloroisopentene generated by chloro addition reaction is esterified and subjected to alkaline hydrolysis to generate methyl butenol, 1-chloroisopentene is converted into isopentenol, and the methyl butenol and the isopentenol are separated by rectification, so that the direct separation of the 3-chloroisopentene and the 1-chloroisopentene by adopting the traditional rectification is avoided, and the problems of corrosion on equipment, toxicity of chloride, certain damage to the chloride due to high temperature and the like caused by the existing chloroisopentene rectification are solved. The separated 10% of methyl butenol is reused in the chloro-addition reaction, so that about 10% of 3-chloro isoamylene generated in the chloro-addition reaction is effectively reused, the balance ratio of 1: 8-1: 9 of the 3-chloro isoamylene and 1-chloro isoamylene is formed again, the yield of the isoamylene alcohol relative to the isoprene can be improved to 93-95% from 80-85% by recycling the method, and meanwhile, the generation of waste can be greatly reduced.
As the addition reaction of isoprene and hydrogen chloride generates about 10 percent of 3-chloroisopentene, methyl butenol added in the raw material can be chlorinated firstly to generate the 3-chloroisopentene, thereby leading the isoprene to react completely.
The method for improving the yield of the prenol prepared by the chlorination method comprises the following specific steps:
1) dissolving isoprene and methyl butenol in toluene at the molar ratio of 9:1, slowly adding concentrated hydrochloric acid dropwise when the temperature is reduced to-20 to-5 ℃, continuously stirring, keeping the temperature, and continuously stirring for reaction;
2) after reacting for a period of time, taking the organic layer for gas chromatography analysis, and stopping stirring when the isoprene content in the organic layer is 1.5-3.5%, and finishing the reaction;
3) standing and layering the reaction liquid obtained in the step 2), introducing hydrogen chloride into a water layer to become concentrated hydrochloric acid, and sleeving the concentrated hydrochloric acid into the chloro addition reaction in the step 1), removing water in an organic layer, directly adding anhydrous formate or acetate, heating to 80-120 ℃ to perform esterification reaction, wherein 3-chloro isoamylene does not participate in esterification, after the esterification reaction is finished, 1-chloro isoamylene is converted into isopentenol formate or isopentenol acetate, 3-chloro isoamylene is mixed and dissolved in the isopentenol formate or the isopentenol acetate, and filtering out chloride salt solids from the organic layer;
4) and 3) adding the organic layer obtained in the step 3) into an alkali solution for hydrolysis reaction, converting the prenol formate or prenol acetate into prenol, converting 3-chloroisopentene into methyl butenol, rectifying the organic layer to separate out the methyl butenol, toluene and prenol, and recycling the methyl butenol and the toluene into the chloro addition reaction in the step 1) to realize recycling of the 3-chloroisopentene.
Further, in the step 1), the mass concentration of the concentrated hydrochloric acid is 32-36%.
Further, the volume ratio of the mixture of isoprene and methyl butenol to toluene of the raw materials used in the step 1) is 0.2-1: 1; the volume ratio of the mixture of isoprene and methyl butenol to concentrated hydrochloric acid is 0.2-0.5: 1.
Further, the reaction time of the step 1) is 3-10 hours; the reaction time of the step 3) is 5-10 hours.
Further, in the step 3), the feeding molar ratio of the chloroisoamylene to the anhydrous formate or acetate is 1: 1-1.5.
Further, in the step 4), the mass concentration of the alkali solution is 10-50%.
Furthermore, a catalyst tetraethylammonium bromide or hexadecyltrimethylammonium bromide is also added during esterification.
Further, the alkali solution is sodium hydroxide solution or potassium hydroxide solution.
Further, the anhydrous formate or acetate is sodium salt or potassium salt.
The invention avoids the direct separation of 3-chloroisoamylene and 1-chloroisoamylene by adopting the traditional rectification, and solves the problems of equipment corrosion, toxic chloride, certain damage to the chloride due to high temperature and the like caused by the rectification of the chloroisoamylene at present; the recycling and reusing of the 3-chloroisopentene are realized, the generated 3-chloroisopentene is effectively utilized, the discharge of waste is reduced, the total yield of the isopentenol relative to the isoprene is improved, the yield is improved to 93-95% from the existing 80-85%, the production cost of the isopentenol is effectively reduced, and the market competitiveness of the product is improved.
Detailed Description
The present invention will be described in more detail by the following examples, but the present invention is not limited to these examples in any way, and the content and purity of the product in the present invention are measured by gas chromatography.
Example 1
Respectively putting 90g of isoprene and 10g of methyl butenol into a 500ml three-necked bottle, then putting 100g of toluene as a solvent, fully stirring and cooling until the temperature of the solution in the three-necked bottle is reduced to-10 ℃, starting to slowly dropwise add 400ml of concentrated hydrochloric acid (32%), after half an hour, keeping the temperature of-10 ℃ for reaction for about 5 hours, sampling and carrying out gas chromatographic analysis, stopping the reaction when the contents of isoprene, 3-chloroisopentene and 1-chloroisopentene in the reaction system are respectively about 3%, 10% and 86%, and the content of impurity dichloroisopentane is about 1%, and standing and layering.
125g of sodium acetate and 1.5g of tetraethylammonium bromide are added into the organic layer, the mixture is placed in a 500ml three-necked bottle and reacts for about 6 hours at the temperature of 100 ℃, sampling gas chromatography analysis is carried out, when the contents of isoprene, 3-chloroisopentene and isopentenol acetate in the reaction system are respectively about 3%, 10% and 85%, the reaction is stopped, the organic layer and NaCl solid are separated by filtration, and the esterified organic layer is used for later use.
Adding 200ml of 30% sodium hydroxide solution into the organic layer of the ester, carrying out alkaline hydrolysis for 3 hours at 75 ℃, sampling, carrying out gas chromatography analysis, and stopping reaction and layering when the contents of isoprene, methyl butenol and isopentenol in the reaction system are respectively 3%, 10% and 85%. The organic layer is rectified, the separated light components are isoprene, methyl butenol and toluene, and the positive component is isopentenol. The toluene solution of isoprene and methyl butenol was applied to the chloro-addition reaction, and the yield of prenol with respect to isoprene was 95%.
Example 2
Respectively putting 90g of isoprene and 10g of methyl butenol into a 500ml three-necked bottle, then putting 100g of toluene as a solvent, fully stirring and cooling until the temperature of the solution in the three-necked bottle is reduced to-15 ℃, starting to slowly dropwise add 400ml of concentrated hydrochloric acid (35%), after half an hour, keeping the temperature of-10 ℃ for reaction for about 5 hours, sampling and carrying out gas chromatographic analysis, wherein the contents of isoprene, 3-chloroisopentene and 1-chloroisopentene in a reaction system are respectively about 2%, 12% and 84%, the content of impurity dichloroisopentane is about 2%, stopping the reaction, and standing and layering.
125g of sodium acetate and 1.5g of tetraethylammonium bromide are added into the organic layer, the mixture is placed in a 500ml three-necked bottle and reacts for about 6 hours at the temperature of 100 ℃, sampling gas chromatography analysis is carried out, when the contents of isoprene, 3-chloroisopentene and isopentenol acetate in the reaction system are respectively about 2%, 12% and 84%, the reaction is stopped, the organic layer and NaCl solid are separated by filtration, and the esterified organic layer is used for later use.
Adding 200ml of 30% sodium hydroxide solution into the organic layer of the ester, carrying out alkaline hydrolysis at 75 ℃ for 3 hours, sampling, carrying out gas chromatography analysis, and stopping reaction and layering when the contents of isoprene, methyl butenol and isopentenol in the reaction system are respectively about 2%, 11% and 83%. The organic layer is rectified, the separated light components are isoprene, methyl butenol and toluene, and the positive component is isopentenol. The toluene solution of isoprene and methyl butenol was mechanically used in the chloroaddition reaction, and the yield of prenol relative to isoprene was 92.6%.
Example 3
Respectively putting 90g of isoprene and 10g of methylbutenol into a 500ml three-necked bottle, fully stirring and cooling until the temperature of a solution in the three-necked bottle is reduced to-10 ℃, slowly dropwise adding 400ml of concentrated hydrochloric acid (32%), after half an hour, keeping the temperature of-10 ℃ for reaction for about 4 hours, sampling and analyzing by gas chromatography, respectively keeping the content of isoprene, 3-chloroisoamylene and 1-chloroisoamylene in a reaction system to be about 1.5%, 13% and 83%, keeping the content of impurity dichloroisopentane to be about 2.5%, stopping the reaction, and standing and layering.
125g of sodium acetate and 1.5g of tetraethylammonium bromide are added into the organic layer, the mixture is placed in a 500ml three-necked bottle and reacts for about 6 hours at the temperature of 100 ℃, sampling gas chromatography analysis is carried out, when the contents of isoprene, 3-chloroisopentene and isopentenol acetate in the reaction system are respectively 1.5%, 13% and 83%, the reaction is stopped, the organic layer and NaCl solid are separated by filtration, and the esterified organic layer is used for later use.
Adding 200ml of 30% sodium hydroxide solution into the organic layer of the ester, carrying out alkaline hydrolysis at 75 ℃ for 3 hours, sampling and carrying out gas chromatography analysis, and stopping reaction and layering when the contents of isoprene, methyl butenol and isopentenol in the reaction system are respectively about 1.5%, 13% and 82%. The organic layer is rectified, the separated light components are isoprene, methyl butenol and toluene, and the positive component is isopentenol. Isoprene and methyl butenol are mechanically applied to the chloro addition reaction, and the yield of the prenol relative to isoprene is 91.6%.
Example 4
Respectively putting 90g of isoprene and 10g of methyl butenol into a 500ml three-necked bottle, then putting 100g of toluene as a solvent, fully stirring and cooling until the temperature of the solution in the three-necked bottle is reduced to-10 ℃, starting to slowly dropwise add 400ml of concentrated hydrochloric acid (32%), after half an hour, keeping the temperature of-10 ℃ for reaction for about 5 hours, sampling and carrying out gas chromatographic analysis, and stopping the reaction and carrying out static layering when the contents of isoprene, 3-chloroisopentene and 1-chloroisopentene in a reaction system are respectively 3.2%, 10.5% and 85.3%, and the content of impurity dichloroisopentane is about 1%.
Adding 135g of potassium acetate and 1.5g of tetraethylammonium bromide into the organic layer, placing the organic layer into a 500ml three-necked bottle, reacting for about 8 hours at 100 ℃, sampling and carrying out gas chromatography analysis, stopping the reaction when the contents of isoprene, 3-chloroisopentene and isopentenol acetate in the reaction system are respectively 3.3%, 10.5% and 84%, filtering and separating out an organic layer and KCl solid, and using an esterified organic layer for later use.
And adding 220ml of 30% potassium hydroxide solution into the organic layer of the ester, carrying out alkaline hydrolysis at 75 ℃ for 2.5 hours, sampling, carrying out gas chromatography analysis, and stopping reaction and layering when the contents of isoprene, methyl butenol and isopentenol in the reaction system are respectively 3.3%, 10.5% and 84%. The organic layer is rectified, the separated light components are isoprene, methyl butenol and toluene, and the positive component is isopentenol. The toluene solution of isoprene and methyl butenol was used in the chloroaddition reaction, and the yield of prenol to isoprene was 93.8%.
Example 5
Respectively putting 90g of isoprene and 10g of methyl butenol into a 500ml three-necked bottle, then putting 100g of toluene as a solvent, fully stirring and cooling until the temperature of the solution in the three-necked bottle is reduced to-10 ℃, starting to slowly dropwise add 400ml of concentrated hydrochloric acid (32%), after half an hour, keeping the temperature of-10 ℃ for reaction for about 5 hours, sampling and carrying out gas chromatographic analysis, stopping the reaction when the contents of isoprene, 3-chloroisopentene and 1-chloroisopentene in the reaction system are respectively 3.3%, 9.8% and 86%, and the content of impurity dichloroisopentane is about 1.4%, and carrying out static layering.
125g of sodium acetate and 2.5g of hexadecyl trimethyl ammonium bromide are added into the organic layer, the mixture is placed into a 500ml three-necked bottle, the reaction is carried out for about 10 hours at the temperature of 100 ℃, sampling gas chromatography analysis is carried out, the reaction is stopped when the contents of isoprene, 3-chloroisopentene and isopentenol acetate in the reaction system are respectively about 3.5%, 10.1% and 82%, the reaction is filtered, an organic layer and NaCl solid are separated, and an esterified substance organic layer is used for standby.
Adding 200ml of 30% sodium hydroxide solution into the organic layer of the ester, carrying out alkaline hydrolysis at 75 ℃ for 3 hours, sampling and carrying out gas chromatography analysis, and stopping reaction and layering when the contents of isoprene, methyl butenol and isopentenol in the reaction system are respectively about 3.6%, 10.3% and 81.7%. The organic layer is rectified, the separated light components are isoprene, methyl butenol and toluene, and the positive component is isopentenol. The toluene solution of isoprene and methyl butenol was used in the chloro-addition reaction, and the yield of prenol with respect to isoprene was 90.8%.
Example 6
Respectively putting 90g of isoprene and 10g of methyl butenol into a 500ml three-necked bottle, then putting 100g of toluene as a solvent, fully stirring and cooling until the temperature of the solution in the three-necked bottle is reduced to-10 ℃, starting to slowly dropwise add 400ml of concentrated hydrochloric acid (32%), after half an hour, keeping the temperature of-10 ℃ for reaction for about 5 hours, sampling and carrying out gas chromatographic analysis, and stopping the reaction and standing for layering when the contents of isoprene, 3-chloroisopentene and 1-chloroisopentene in a reaction system are respectively 2.7%, 9.7% and 86.3%, and the content of impurity dichloroisopentane is about 1.1%.
Adding 135g of potassium acetate and 2.5g of hexadecyl trimethyl ammonium bromide into the organic layer, placing the organic layer into a 500ml three-necked bottle, reacting for about 10 hours at 100 ℃, sampling and analyzing by gas chromatography, stopping the reaction when the contents of isoprene, 3-chloroisopentene and isopentenol acetate in the reaction system are respectively about 3.1%, 10.4% and 80.4%, filtering and separating out an organic layer and KCl solid, and using an esterified substance organic layer for later use.
And adding 220ml of 30% potassium hydroxide solution into the organic layer of the ester, carrying out alkaline hydrolysis at 75 ℃ for 2.5 hours, sampling, carrying out gas chromatography analysis, and stopping reaction and layering when the contents of isoprene, methyl butenol and isopentenol in the reaction system are respectively about 3.4%, 10.2% and 80.3%. The organic layer is rectified, the separated light components are isoprene, methyl butenol and toluene, and the positive component is isopentenol. The toluene solution of isoprene and methyl butenol was used in the chloro-addition reaction, and the yield of prenol with respect to isoprene was 90.2%.
Example 7
Respectively putting 90g of isoprene and 10g of methyl butenol into a 500ml three-necked bottle, then putting 100g of toluene as a solvent, fully stirring and cooling until the temperature of the solution in the three-necked bottle is reduced to-10 ℃, starting to slowly dropwise add 400ml of concentrated hydrochloric acid (32%), after half an hour, keeping the temperature of-10 ℃ for reaction for about 5 hours, sampling and carrying out gas chromatographic analysis, and stopping the reaction and standing for layering when the contents of isoprene, 3-chloroisopentene and 1-chloroisopentene in the reaction system are respectively 2.6%, 9.4% and 87.1%, and the content of impurity dichloroisopentane is about 0.9%.
112g of anhydrous sodium formate and 1.5g of tetraethylammonium bromide are added into the organic layer, the mixture is placed into a 500ml three-necked bottle and reacts for about 12 hours at 100 ℃, sampling gas chromatography analysis is carried out, when the contents of isoprene, 3-chloroisopentene and isopentenol formate in the reaction system are respectively about 3.1%, 9.8% and 82.3%, the reaction is stopped, the organic layer and NaCl solid are separated by filtration, and the esterified organic layer is used for later use.
And adding 220ml of 30% potassium hydroxide solution into the organic layer of the ester, carrying out alkaline hydrolysis at 75 ℃ for 2.5 hours, sampling, carrying out gas chromatography analysis, and stopping reaction and layering when the contents of isoprene, methyl butenol and isopentenol in the reaction system are respectively about 3.2%, 9.7% and 82.5%. The organic layer is rectified, the separated light components are isoprene, methyl butenol and toluene, and the positive component is isopentenol. The toluene solution of isoprene and methyl butenol was used in the chloroaddition reaction, and the yield of prenol relative to isoprene was 92.1%.
Comparative example 1
Putting 100g of isoprene into a 500ml three-mouth bottle, fully stirring and cooling until the temperature of a solution in the three-mouth bottle is reduced to-10 ℃, slowly dropwise adding 400ml of concentrated hydrochloric acid (32%), after half an hour of dropwise adding, keeping the temperature of-10 ℃ for about 4 hours for reaction, sampling and carrying out gas chromatographic analysis, wherein the contents of isoprene, 3-chloroisoamylene and 1-chloroisoamylene in a reaction system are respectively about 2.5%, 12% and 82%, the content of impurity dichloroisopentane is about 3.5%, stopping the reaction, and standing and layering. And rectifying the organic layer to separate isoprene, 3-chloroisopentene and 1-chloroisopentene, and recycling the isoprene to the chloro addition reaction.
Adding 100g of toluene, 120g of sodium acetate and 1.5g of tetraethylammonium bromide into 1-chloroisopentene, placing the mixture in a 500ml three-necked bottle, reacting for about 6 hours at 100 ℃, sampling and analyzing by gas chromatography, stopping the reaction when the 1-chloroisopentene in the reaction system is basically converted into isopentenol acetate, filtering and separating an organic layer and NaCl solid, and using an esterified organic layer for later use.
And adding 200ml of 30% sodium hydroxide solution into the esterified organic layer, carrying out alkaline hydrolysis at 75 ℃ for 3 hours, sampling, carrying out gas chromatographic analysis, stopping the reaction when the isopentenol acetate in the reaction system is completely converted into the isopentenol, and layering. And rectifying the organic layer to separate toluene and isopentenol, wherein the yield of the isopentenol relative to isoprene is 80.3%.
Comparative example 2
Putting 100g of isoprene into a 500ml three-mouth bottle, fully stirring and cooling until the temperature of a solution in the three-mouth bottle is reduced to-15 ℃, slowly dropwise adding 400ml of concentrated hydrochloric acid (35%), after half an hour, keeping the temperature of-10 ℃ for reaction for about 4 hours, sampling and carrying out gas chromatography analysis, wherein the contents of isoprene, 3-chloroisopentene and 1-chloroisopentene in a reaction system are respectively about 1.8%, 13% and 81.5%, the content of impurity dichloroisopentane is about 3.7%, stopping the reaction, and standing and layering. And rectifying the organic layer to separate isoprene, 3-chloroisopentene and 1-chloroisopentene, and recycling the isoprene to the chloro addition reaction.
Adding 100g of toluene, 120g of sodium acetate and 1.5g of tetraethylammonium bromide into 1-chloroisopentene, placing the mixture in a 500ml three-necked bottle, reacting for about 6 hours at 100 ℃, sampling and analyzing by gas chromatography, stopping the reaction when the 1-chloroisopentene in the reaction system is basically converted into isopentenol acetate, filtering and separating an organic layer and NaCl solid, and using an esterified organic layer for later use.
And adding 200ml of 30% sodium hydroxide solution into the esterified organic layer, carrying out alkaline hydrolysis at 75 ℃ for 3 hours, sampling, carrying out gas chromatographic analysis, stopping the reaction when the isopentenol acetate in the reaction system is completely converted into the isopentenol, and layering. And rectifying the organic layer to separate toluene and isopentenol, wherein the yield of the isopentenol relative to isoprene is 78.8%.
Claims (10)
1. A method for improving the yield of prenol prepared by a chlorination method is characterized in that methyl butenol is added in the chlorination reaction of isoprene, the molar ratio of isoprene to methyl butenol is 9:1, 3-chloroisopentene obtained by the chlorination reaction is not separated from 1-chloroisopentene, anhydrous formate or acetate is directly added for esterification, 1-chloroisopentene is converted into prenol formate or prenol acetate, and 3-chloroisopentene is dissolved in the prenol formate or prenol acetate; and then carrying out hydrolysis reaction in an alkali solution, after the hydrolysis is finished, converting the prenol formate or prenol acetate into prenol, converting 3-chloroisopentene into methyl butenol, rectifying the obtained organic layer to separate out the methyl butenol and the prenol, and recycling the methyl butenol to the chloro addition reaction.
2. The method of claim 1, comprising the following steps:
1) dissolving isoprene and methyl butenol in toluene, slowly dripping concentrated hydrochloric acid when the temperature is reduced to-20 to-5 ℃, continuously stirring, preserving heat after dripping is finished, and continuously stirring for reaction;
2) after reacting for a period of time, taking the organic layer for gas chromatography analysis, and stopping stirring when the isoprene content in the organic layer is 1.5-3.5%, and finishing the reaction;
3) standing and layering the reaction liquid obtained in the step 2), introducing hydrogen chloride into a water layer to become concentrated hydrochloric acid, and sleeving the concentrated hydrochloric acid into the chloro addition reaction in the step 1), removing water in an organic layer, directly adding anhydrous formate or acetate, heating to 80-120 ℃ to perform esterification reaction, wherein 3-chloro isoamylene does not participate in esterification, after the esterification reaction is finished, 1-chloro isoamylene is converted into isopentenol formate or isopentenol acetate, 3-chloro isoamylene is mixed and dissolved in the isopentenol formate or the isopentenol acetate, and filtering out chloride salt solids from the organic layer;
4) and 3) adding the organic layer obtained in the step 3) into an alkali solution for hydrolysis reaction, converting the prenol formate or prenol acetate into prenol, converting 3-chloroisopentene into methyl butenol, rectifying the organic layer to separate out the methyl butenol, toluene and prenol, and recycling the methyl butenol and the toluene into the chloro addition reaction in the step 1) to realize recycling of the 3-chloroisopentene.
3. The method of claim 2, wherein: in the step 1), the mass concentration of the concentrated hydrochloric acid is 32-36%.
4. The method of claim 2, wherein: the volume ratio of the mixture of isoprene and methyl butenol to toluene of the raw materials used in the step 1) is 0.2-1: 1; the volume ratio of the mixture of isoprene and methyl butenol to concentrated hydrochloric acid is 0.2-0.5: 1.
5. The method of claim 2, wherein: the reaction time of the step 1) is 3-10 hours; the reaction time of the step 3) is 5-10 hours.
6. The method of claim 2, wherein: in the step 3), the feeding molar ratio of the chloroisopentene to the formate or the acetate is 1: 1-1.5.
7. The method of claim 2, wherein: in the step 4), the mass concentration of the alkali solution is 10-50%.
8. The method according to claim 1 or 2, characterized in that the esterification is further charged with a catalyst tetraethylammonium bromide or cetyltrimethylammonium bromide.
9. The method according to claim 1 or 2, wherein the alkali solution is a sodium hydroxide solution or a potassium hydroxide solution.
10. The process according to claim 1 or 2, wherein the anhydrous formate or acetate salt is a sodium or potassium salt.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5872277A (en) * | 1997-03-10 | 1999-02-16 | Loyola University Of Chicago | Methods for preparing prenyl alcohol |
| CN102381940A (en) * | 2011-07-19 | 2012-03-21 | 赵明江 | Production method of C5 enol |
| CN105175219A (en) * | 2015-08-05 | 2015-12-23 | 山东成泰化工有限公司 | Synthesis method of prenyl alcohol |
-
2016
- 2016-02-16 CN CN201610086502.XA patent/CN107082740B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5872277A (en) * | 1997-03-10 | 1999-02-16 | Loyola University Of Chicago | Methods for preparing prenyl alcohol |
| CN102381940A (en) * | 2011-07-19 | 2012-03-21 | 赵明江 | Production method of C5 enol |
| CN105175219A (en) * | 2015-08-05 | 2015-12-23 | 山东成泰化工有限公司 | Synthesis method of prenyl alcohol |
Non-Patent Citations (1)
| Title |
|---|
| 异戊烯醇的合成研究进展;余慧群等;《化工技术与开发》;20111115;第40卷(第11期);第37-39页 * |
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